1. Field of the Invention
The present invention relates to a device case and a timepiece.
2. Description of Related Art
Device cases of a timepiece and the like are conventionally provided with windproof members, such as transparent glass, on their viewing faces.
The device cases of a timepiece and the like, which accommodate precision electronic devices, should have high-pressure waterproofness and shock resistance.
A windproof member satisfying such requirements can be fixed to a device case through bonding of the windproof member to an opening in the device case or press-fitting of the windproof member into the opening of the device case with a packing disposed therebetween.
In the case where the device case is a resin device case composed of synthetic resin, such as a plastic (hereinafter, such a device case is also referred to as “resin case”), the resin case undergoes a higher level of expansion and contraction due to thermal expansion and deformation due to high pressure compared to metal cases.
Thus, the windproof member is usually press-fitted into the resin case with a packing disposed therebetween such that the windproof member can follow such expansion/contraction and deformation (for example, refer to Japanese Patent Application Laid-Open Publication No. 2003-4869).
Unfortunately, press-fitting of the windproof member applies a large force to the device case and thus may cause deformation of the device case.
Thus, the deformation of a device case should be prevented by further providing metal parts on the interior and/or exterior of the device case for correcting the shape of the device case, such as an interior cover inserted into the resin case or a bezel fitted to the exterior of the resin case, to reinforce the device case to prevent deformation.
Unfortunately, in such a structure for preventing deformation, the packing and the metal parts for reinforcement increases the outer diameter of the windproof member and the thickness of the resin of the device case, resulting in increased dimensions of the entire device case. The thickness of the resin of the device case should be increased to bear the force applied to the windproof member during press-fitting.
This increases the dimensions and weight of the device case, which offsets the advantage of a resin case of light weight and decreases design flexibility compared to those of a metal device case. This leads to an increase in restriction on the design.